The invention generally relates to electrophoretic mass spectrometry probes and systems and methods of uses thereof. In certain aspects, the invention provides a mass spectrometry probe having a hollow body with a distal tip, an electrically conductive hollow conduit, and an electrode. The electrically conductive hollow conduit may be operably coupled to a reservoir and a power source, and the electrically conductive hollow conduit may be configured to transport a liquid sample into the hollow body and polarize the liquid sample as it flows through the electrically conductive hollow conduit and into in the hollow body. The electrode and the electrically conductive hollow conduit are disposed within the hollow body (e.g., at different heights within the hollow body).